Assessment of Heavy Metal Status in Groundwater around a Dumpsite in Ibadan, South-Western Nigeria.

Abstract

Groundwater contamination within the vicinity of dumpsites has elicited public health concern in recent time. The study assessed the impact of waste dump on the groundwater quality with special reference to heavy metal contamination. Twenty five composite groundwater samples were collected within and some distances from the vicinity of dumpsite at different axes (downslope and upslope) location. Water samples were analyzed for heavy metal (Zn, Cu, Pb, Fe, Ni, Cr, Co, Mn, As and Ni) concentrations using ICP-AES instrumentation techniques. Data were analyzed using descriptive statistic, graphics and contamination indices (Contamination factor and Degree of Contamination). Water samples from downslope location revealed high metal concentrations in comparison to upslope location. Heavy metal concentrations showed reductions with increased in distances from waste dumpsite. The Contamination Factors (CF) of heavy metal concentration in water were Fe (1.04), Zn (1.14), Cu (1.07), Pb (1.07), Cd (0.95), Ni (0.99) and Co (0.87); and Degree of Contamination (Cd) in water was 8.0 indicating groundwater in study area was moderately contaminated. The study showed that toxic heavy metals from waste materials in the dumpsite had contaminated the groundwater. Resident in this location may in future be exposed to greater risk, hence re-designing of the dumpsite construction to sanitary landfill with clay or plastic liners and adoption of clean-up technology for heavy metals are recommended.